Examine source code of Reload All Tabs

{
  "manifest_version": 2,
  "name": "Reload All Tabs",
  "version": "3.0",
  "description": "Reload all open tabs with one click.",
  "permissions": [
    "tabs"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icon.png",
      "48": "icon.png",
      "128": "icon.png"
    }
  },
  "icons": {
    "16": "icon.png",
    "48": "icon.png",
    "128": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{63c8f677-7e9f-45eb-9a6b-adeda4e84e36}"
    }
  }
}